1. Field of the Invention
This invention relates to a novel process for producing tetrachloroethylene or tetrachloromethane (carbon tetrachloride). More particularly, it relates to a process for producing tetrachloroethylene by a dechlorination dimerization of tetrachloromethane in the presence of a molten salt catalyst, and to a process for producing tetrachloromethane by the thermal chlorination decomposition of a completely chlorinated saturated and/or unsaturated hydrocarbon having from 2 to 4 carbon atoms in the presence of a molten salt catalyst.
2. Description of the Prior Art
It has heretofore been known to produce tetrachloroethylene from tetrachloromethane according to the following thermal equilibrium reaction: EQU 2CCl.sub.4 .revreaction. C.sub.2 Cl.sub.4 + 2Cl.sub.2
However, the rate of this reaction is extremely low and, for example, this reaction will not proceed at all at a temperature below 500.degree. C. Accordingly, the production of tetrachloroethylene in accordance with this reaction on an industrial scale must be conducted at a temperature above about 550.degree. C.
Also, it has hitherto been known to produce tetrachloromethane by the thermal chlorination decomposition reaction shown in the following equation wherein tetrachloroethylene is reacted with chlorine. EQU C.sub.2 Cl.sub.4 + 2Cl.sub.2 .revreaction. 2CCl.sub.4
However, the rate of this reaction is also extremely low and, for example, this reaction will not proceed at a temperature below 500.degree. C. Therefore, this reaction on an industrial scale must be conducted at a temperature of about 550.degree. C. using a large excess of chlorine, e.g., in an amount of twice the theoretical amount.
If the reaction for converting tetrachloromethane to tetrachloroethylene or vice versa can be conducted at a lower temperature and at a higher reaction rate, it will be extremely valuable from an industrial viewpoint. However, such a process has not yet been established.
An object of the present invention is to provide a novel and economical process for producing tetrachloroethylene from tetrachloromethane.
Another object of the present invention is to provide a novel and economical process for producing tetracholomethane from a chlorinated hydrocarbon as a raw material.